AFN-1252 is a potent inhibitor of enoyl-ACP reductase from Burkholderia pseudomallei--Crystal structure, mode of action, and biological activity.

Abstract

Melioidosis is a tropical bacterial infection caused by Burkholderia pseudomallei (B. pseudomallei; Bpm), a Gram-negative bacterium. Current therapeutic options are largely limited to trimethoprim-sulfamethoxazole and β-lactam drugs, and the treatment duration is about 4 months. Moreover, resistance has been reported to these drugs. Hence, there is a pressing need to develop new antibiotics for Melioidosis. Inhibition of enoyl-ACP reducatase (FabI), a key enzyme in the fatty acid biosynthesis pathway has shown significant promise for antibacterial drug development. FabI has been identified as the major enoyl-ACP reductase present in B. pseudomallei. In this study, we evaluated AFN-1252, a Staphylococcus aureus FabI inhibitor currently in clinical development, for its potential to bind to BpmFabI enzyme and inhibit B. pseudomallei bacterial growth. AFN-1252 stabilized BpmFabI and inhibited the enzyme activity with an IC50 of 9.6 nM. It showed good antibacterial activity against B. pseudomallei R15 strain, isolated from a melioidosis patient (MIC of 2.35 mg/L). X-ray structure of BpmFabI with AFN-1252 was determined at a resolution of 2.3 Å. Complex of BpmFabI with AFN-1252 formed a symmetrical tetrameric structure with one molecule of AFN-1252 bound to each monomeric subunit. The kinetic and thermal melting studies supported the finding that AFN-1252 can bind to BpmFabI independent of cofactor. The structural and mechanistic insights from these studies might help the rational design and development of new FabI inhibitors.

• Authors: Krishnamurthy Narasimha Rao, Anirudha Lakshminarasimhan, Sarah Joseph, Swathi U Lekshmi, Ming-Seong Lau, Mohammed Takhi, Kandepu Sreenivas, Sheila Nathan, Rohana Yusof, Noorsaadah Abd Rahman, Murali Ramachandra, Thomas Antony, Hosahalli Subramanya
• Journal: Protein science : a publication of the Protein Society (Protein Sci) Vol. 24 Issue 5 Pg. 832-40 (May 2015) ISSN: 1469-896X [Electronic] United States
• PMID: 25644789 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2015 The Protein Society.

Chemical References

• API 1252
• Anti-Bacterial Agents
• Benzofurans
• Pyrones
• Enoyl-(Acyl-Carrier-Protein) Reductase (NADH)

Topics

• Anti-Bacterial Agents (chemistry, therapeutic use)
• Benzofurans (chemistry, therapeutic use)
• Burkholderia pseudomallei (drug effects, enzymology)
• Crystallography, X-Ray
• Enoyl-(Acyl-Carrier-Protein) Reductase (NADH) (antagonists & inhibitors, chemistry, metabolism)
• Humans
• Kinetics
• Melioidosis (drug therapy, enzymology, microbiology)
• Pyrones (chemistry, therapeutic use)
• Staphylococcal Infections (drug therapy, microbiology)